1. Field of the Invention
The invention disclosed is primarily for use with magnetic tape units associated with data processing systems. The variable cyclic redundancy character detector may be used with seven or nine track magnetic tapes with character densities of either 800, 556 or 200 characters per inch (cpi).
2. Description of the Prior Art
Prior art mechanism for detecting the CCC and/or LCC are fixed, non-variable devices that must detect the LCC or CCC at a fixed point in time after data block is read or the data block is deemed to have been read in error. No known mechanisms provide for compacting or extending the time period from the end of the data block to when the CCC or LCC may appear and, consequently, if the CCC, which should appear four character spaces after the end of the data block but had been inadvertently written five character spaces after the data block, the data block would be considered in error.